220 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



their origins, each borne on a distinct shoulderlike process of the 

 stem and separated from it by a deeply incised node. Hydrothecae 

 strictly alternate, usually about six to each internode, immersed for 

 about three-fourths their entire length. Distal portion abruptly 

 constricted and bending outward from the flask-shaped body. Mar- 

 gin pitcher shaped and bearing a single adcauline operculum, as is 

 characteristic of the genus. The hydranths are not sufficiently well 

 preserved for description. 



Gonosome. — Gonangia borne on upper side of branches, small for 

 this genus, oblong-ovate in shape and without the spines character- 

 istic of Diphasm. There are indications of an internal marsupium 

 which in some instances seems to have broken out of the aperture 

 and formed a sort of an acrocyst. The indications are that these 

 gonangia bear male reproductive elements. 



Locality. — Dredging station 5325, off northern Luzon, Hermanos 

 Island, 18° 34' 15" N., 121° 51' 15" E.; depth, 224 fathoms. 



Holotype.— -Cat, No. 42178, U.S.N.M. 



This species comes nearest to Diphasia kincaidi (Nutting), 18 from 

 which it differs in having strictly alternate instead of subopposite 

 hydrothecae, which are less robust than in the former species. The 

 gonangia are a good deal the same in the two, except that those of 

 D. kincaidi have no internal marsupium. 



The present writer has always stood for a statute of limitations 

 for zoological names, and therefore does not follow Stechow, 19 who 

 regards Diphasia of Agassiz as a synonym of Nigellastrum of Oken, 

 1815. 



PASYTHEA QUADRIDENTATA (Ellis and Solander) 



Sertularia quad rid entata Ellis and Solander, Nat. H. Zooph.. 1786, p. 57. 

 Pasythed quadridentata Esper, Die rflaiizenthiere in Abbildungen. vol. 3, 



1788, p. 237. 

 Pasythea, species, Inaba, Hydroida of the West Coast, Kishu, 1892, figs. 



11-14. 

 Pasythea nodosa Hargitt, Notes on a few Coelenterates of Wood's Hole 



(Contr. Zool. Lab. Syracuse Univ.) 1908, pp. 114-117. 

 Pasythea quadridentata Fraser, Some Hydroids of Beaufort, N. C, 1912, 



p. 372. 



I have no doubt that Fraser was right in his decision that Har- 

 gitt's P. nodosa is the same as the original Pasythea quadridentata, 

 as proved by the finding of the gonangia. 



In the specimen secured by the Albatross in 1907 the gonangia are 

 also present and exactly like those figured by me in American Hy- 

 droids (pt. 2, pi. 13, fig. 5). 



18 Thuiaria elegans Nutting, Hydroids of the Harriman Alaska Expedition, 1901, p. 187. 

 Diphasia kincaidi Nutting, Hydroids from Alaska and Puget Sound, 1899, p. 743. 

 " Hydroidenfauna des Mittelmeeres, Amerikas u. s. w., 1923, p 160 



